Abstract:

A system is provided for the treatment of wounds by applying a negative
pressure to a wound. The system comprises an electronically controlled
suction regulator that comprises: a vacuum regulator, a coupler for
coupling the vacuum regulator to an external vacuum source, a valve
connected to the vacuum regulator for supplying a negative pressure to
the wound, and a control circuit for generating control signals for
controlling the valve so that negative pressure may be continuously or
intermittently supplied to the wound. The system further comprises a
wound dressing provided at the wound site and coupled to the electrically
operated valve. The wound dressing comprises a wound dressing pad for
placing over the wound, and a wound drape provided over the wound
dressing pad and the wound site for sealing the wound site for
application of the negative pressure.

Claims:

1. A system for the treatment of wounds by applying a negative pressure to
a wound site, the system comprising:an electronically controlled suction
regulator, said suction regulator comprising:a vacuum regulator,a coupler
for coupling said vacuum regulator to an external vacuum source,a valve
connected to said vacuum regulator for supplying a negative pressure to
the wound site, anda control circuit for generating control signals for
controlling said valve so that negative pressure may be continuously or
intermittently supplied to the wound site; anda wound dressing provided
at the wound site and coupled to said electrically operated valve, said
wound dressing comprising:a wound dressing pad for placing over the
wound, anda wound drape provided over said wound dressing pad and the
wound site for securing said wound dressing pad and sealing the wound
site for application of the negative pressure.

2. The system of claim 1 and further comprising:a canister operatively
coupled to said vacuum regulator for receiving and storing fluids drawn
from the wound.

3. The system of claim 2 and further comprising:a fluid level alarm
provided in said canister for supplying a fluid level alarm signal to
said control circuit when said canister is full of fluid.

4. The system of claim 3 and further comprising:a second canister
operatively coupled to said vacuum regulator for receiving and storing
fluids drawn from the wound, wherein said control circuit controls said
electronically controlled valve to apply the vacuum drawn by said vacuum
regulator to said second canister when said fluid level alarm signal is
received.

5. The system of claim 1 wherein said control circuit comprises a
processor, a display coupled to said processor, and at least one user
interface switch coupled to said processor.

6. The system of claim 1 and further comprising a transmitter for
transmitting information from said suction regulator to a healthcare
facility records database.

7. The system of claim 6, wherein the information transmitted by said
transmitter includes any one or more of the following: times at which
negative pressure was applied to the wound, a pressure applied,
intermittence cycles, times at which settings were changed along with new
settings, leak detection alarm times, full canister alarms times, and
readings from a flow sensor.

8. The system of claim 6, wherein said transmitter is a wireless
transmitter for transmitting the information wirelessly to the healthcare
facility records database.

9. The system of claim 1 and further comprising a flow sensor for sensing
a flow rate from the wound site, wherein an alarm is sounded if the flow
rate exceeds a threshold.

10. The system of claim 1, wherein said wound dressing comprises a wound
dressing pad applied over the wound.

11. The system of claim 10, wherein said wound dressing pad is
bio-absorbable.

12. The system of claim 10, wherein said wound dressing pad is a foam pad.

13. The system of claim 1, wherein said wound dressing comprises a drape
secured over the wound site.

14. The system of claim 13, wherein said drape is made of an air permeable
material.

15. The system of claim 13, wherein said drape is made of an non-permeable
material.

16. The system of claim 1, wherein the external vacuum source is a
built-in vacuum system of a healthcare facility.

17. The system of claim 1, wherein the external vacuum source is a
portable vacuum pump.

18. An electronically controlled suction regulator comprising:a vacuum
regulator;a coupler for coupling said vacuum regulator to an external
vacuum source;a valve connected to said vacuum regulator for supplying a
suction at an output;an end user interface for allowing an end user to
select settings relating to characteristics of an intermittent suction
that may be supplied at said output; anda control circuit coupled to said
end user interface for generating control signals for controlling said
valve in accordance with the settings selected by the end user.

19. The suction regulator of claim 18 and further comprising:a canister
operatively coupled to said vacuum regulator for receiving and storing
fluids drawn from the wound.

20. The suction regulator of claim 19 and further comprising:a fluid level
alarm provided in said canister for supplying a fluid level alarm signal
to said control circuit when said canister is full of fluid.

21. The suction regulator of claim 20 and further comprising a flow sensor
for sensing a flow rate from the wound site, wherein an alarm is sounded
if the flow rate exceeds a threshold.

22. The suction regulator of claim 20 and further comprising:a second
canister operatively coupled to said vacuum regulator for receiving and
storing fluids drawn from the wound, wherein said control circuit
controls said electronically controlled valve to apply the vacuum drawn
by said vacuum regulator to said second canister when said fluid level
alarm signal is received.

23. The suction regulator of claim 18 wherein said control circuit
comprises a processor, a display coupled to said processor, and at least
one user interface switch coupled to said processor.

24. The suction regulator of claim 18 and further comprising a transmitter
for transmitting information from said suction regulator to a healthcare
facility records database.

25. The suction regulator of claim 24, wherein the information transmitted
by said transmitter includes any one or more of the following: times at
which negative pressure was applied to the wound, a pressure applied,
intermittence cycles, times at which settings were changed along with new
settings, leak detection alarm times, full canister alarms times, and
readings from a flow sensor.

26. The suction regulator of claim 24, wherein said transmitter is a
wireless transmitter for transmitting the information wirelessly to the
healthcare facility records database.

27. The suction regulator of claim 18 and further comprising a flow sensor
for sensing a flow rate from the wound site, wherein an alarm is sounded
if the flow rate exceeds a threshold.

28. The suction regulator of claim 18, wherein the external vacuum source
is a built-in vacuum system of a healthcare facility.

30. An electronically controlled suction regulator comprising:a vacuum
regulator;a coupler for coupling said vacuum regulator to an external
vacuum source;a valve connected to said vacuum regulator for supplying a
suction at an output;a flow sensor for sensing a flow rate from the wound
site; anda control circuit coupled to said flow sensor for generating
control signals for controlling said valve, said control circuit
generating an alarm signal if the flow rate sensed by said flow sensor
exceeds a threshold.

31. The suction regulator of claim 30, wherein the external vacuum source
is a built-in vacuum system of a healthcare facility.

33. An electronically controlled suction regulator comprising:a vacuum
regulator;a coupler for coupling said vacuum regulator to an external
vacuum source;a valve connected to said vacuum regulator for supplying a
suction at an output;a control circuit for generating control signals for
controlling said valve;a canister operatively coupled to said vacuum
regulator for receiving and storing fluids drawn from the wound; anda
fluid level alarm provided in said canister for supplying a fluid level
alarm signal to said control circuit when said canister is full of fluid.

34. The suction regulator of claim 33 and further comprising a flow sensor
for sensing a flow rate from the wound site, wherein an alarm is sounded
if the flow rate exceeds a threshold.

35. A method of treating a wound at a healthcare facility
comprising:providing a wound dressing over the wound;providing a suction
regulator fluidly connected to the wound dressing;connecting the suction
regulator to a built-in vacuum source of the healthcare facility;
andregulating the vacuum from the vacuum source using the suction
regulator so as to apply a negative pressure to the wound.

Description:

CROSS-REFERENCE TO RELATED APPLICATION

[0001]This application claims the priority benefit of U.S. Provisional
Patent Application No. 60/954,155, filed on Aug. 6, 2007, the entire
disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002]The present invention is generally directed to a system for treating
wounds and, more specifically, to a system for treating wounds by
applying a negative pressure to a wound site and to an electronically
controlled suction regulator for use in a system for applying a negative
pressure to a wound site.

[0003]Wound treatment systems that treat a wound using a vacuum or
negative pressure are known. Examples of such systems are disclosed in
U.S. Pat. Nos. 4,382,441, 4,392,858, 4,655,754, 4,826,494, 4,969,880,
5,100,396, 5,261,893, 5,527,293, 5,636,643, 5,645,081, 6,071,267,
6,117,111, 6,135,116, 6,142,982, 6,174,306, 6,345,623, 6,398,767,
6,520,982, 6,553,998, 6,814,079, 7,198,046, and 7,216,651. These systems
utilize either a manual pump, or a portable vacuum pump to draw air and
fluid from the wound site. Such portable pumps can be expensive and take
up valuable space in the hospital recovery rooms.

SUMMARY OF THE INVENTION

[0004]According to one aspect of the present invention, a system is
provided for the treatment of wounds by applying a negative pressure to a
wound site. The system comprises an electronically controlled suction
regulator. The suction regulator comprising: a vacuum regulator, a
coupler for coupling the vacuum regulator to a built-in vacuum system of
a healthcare facility, an electrically operated valve connected to the
vacuum regulator for supplying a negative pressure to the wound site, and
a control circuit for generating control signals for controlling the
electrically operated valve so that negative pressure may be continuously
or intermittently supplied to the wound site. The system further
comprises a wound dressing provided at the wound site and coupled to the
electrically operated valve. The wound dressing comprises a wound
dressing pad for placing over the wound, and a wound drape provided over
the wound dressing pad and the wound site for securing the wound dressing
pad and sealing the wound site for application of the negative pressure.

[0005]According to another aspect of the present invention, an
electronically controlled suction regulator is provided that comprises a
vacuum regulator; a coupler for coupling the vacuum regulator to an
external vacuum source; a valve connected to the vacuum regulator for
supplying a suction at an output; an end user interface for allowing an
end user to select settings relating to characteristics of an
intermittent suction that may be supplied at the output; and a control
circuit coupled to the end user interface for generating control signals
for controlling the valve in accordance with the settings selected by the
end user.

[0006]According to another aspect of the present invention, an
electronically controlled suction regulator is provided that comprises: a
vacuum regulator; a coupler for coupling the vacuum regulator to an
external vacuum source; a valve connected to the vacuum regulator for
supplying a suction at an output; a flow sensor for sensing a flow rate
from the wound site; and a control circuit coupled to the flow sensor for
generating control signals for controlling the valve, the control circuit
generating an alarm signal if the flow rate sensed by the flow sensor
exceeds a threshold.

[0007]According to another aspect of the present invention, an
electronically controlled suction regulator is provided that comprises: a
coupler for coupling the vacuum regulator to an external vacuum source; a
valve connected to the vacuum regulator for supplying a suction at an
output; a control circuit for generating control signals for controlling
the valve; a canister operatively coupled to the vacuum regulator for
receiving and storing fluids drawn from the wound; and a fluid level
alarm provided in the canister for supplying a fluid level alarm signal
to the control circuit when the canister is full of fluid.

[0008]According to another aspect of the present invention, a method of
treating a wound at a healthcare facility comprising: providing a wound
dressing over the wound; providing a suction regulator fluidly connected
to the wound dressing; connecting the suction regulator to a built-in
vacuum source of the healthcare facility; and regulating the vacuum from
the vacuum source using the suction regulator so as to apply a negative
pressure to the wound.

[0009]These and other features, advantages, and objects of the present
invention will be further understood and appreciated by those skilled in
the art by reference to the following specification, claims, and appended
drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]In the drawings:

[0011]FIG. 1A is a perspective view of a portion of a wound treatment
system according to the present invention;

[0012]FIG. 1B is a front view of a portion of a wound treatment system
according to the present invention;

[0013]FIG. 2 is a fluid flow and electrical circuit diagram in block form
of a wound treatment system according to the present invention;

[0014]FIG. 3 is an electrical circuit diagram in block form of a suction
regulator according to the present invention;

[0015]FIG. 4 is a perspective view of a wound dressing portion that may be
used in the inventive wound treatment system;

[0016]FIG. 5 is a cross-sectional view of the wound dressing portion shown
in FIG. 4 taken along line 2-2;

[0017]FIG. 6 is a top view of the wound dressing portion shown in FIG. 4;

[0018]FIG. 7 is a cut-away perspective view of a portion of the bottom
surface of a drape of the wound dressing portion shown in FIGS. 4 and 6;

[0019]FIG. 8 is a plan view of the bottom surface of an attachment pad
that may be used in the inventive wound treatment system;

[0021]FIG. 10 is a side view of the attachment pad shown in FIG. 8 shown
when in use in the inventive wound treatment system;

[0022]FIG. 11 is a perspective view of a wound dressing portion configured
for attachment to a patient's leg;

[0023]FIG. 12A is a cross-sectional view of an example of a wound dressing
pad that may be used in the inventive wound treatment system; and

[0024]FIG. 12B is a cross-sectional view of another example of a wound
dressing pad that may be used in the inventive wound treatment system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025]Reference will now be made in detail to the presently preferred
embodiments of the invention, examples of which are illustrated in the
accompanying drawings. Wherever possible, the same reference numerals
will be used throughout the drawings to refer to the same or like parts.

[0026]For purposes of description herein, the terms "upper," "lower,"
"right," "left," "rear," "front," "vertical," "horizontal," "top,"
"bottom," and derivatives thereof shall relate to the invention as shown
in the drawings. However, it is to be understood that the invention may
assume various alternative orientations, except where expressly specified
to the contrary. It is also to be understood that the specific devices
illustrated in the attached drawings and described in the following
specification are simply exemplary embodiments of the inventive concepts
defined in the appended claims. Hence, specific dimensions, proportions,
and other physical characteristics relating to the embodiment disclosed
herein are not to be considered as limiting, unless the claims expressly
state otherwise.

[0027]As shown in FIGS. 1A and 1B, a system is provided for treatment of
wounds that includes an electronically controlled suction regulator 20
that connects to an external vacuum source 40. Such an external vacuum
source may include the built-in central vacuum system of a healthcare
facility, central vacuum pump remotely located from the suction
regulator, or a separate portable vacuum pump. Such a connection may be
via an appropriately configured coupler 25 and a supply hose 26. This
system may be used for numerous health provider procedures and devices.
As described further below, this system may have special safety features
built in to protect the patient. The term "built-in" vacuum system is
intended to refer to vacuum systems that are plumbed into the building
structure of a healthcare facility and is not intended to cover a vacuum
pump mounted to a wall or other structure of the patient's room.
"Healthcare facility" is intended to include hospitals, outpatient
treatment facilities, doctors' offices, nursing homes, and any other
facility in which healthcare services are provided.

[0028]As shown in FIGS. 1A, 1B, and 2, the system 10 may include
electronically controlled suction regulator 20 as a single unit having a
housing 22 with integrated regulation of the vacuum and a containment
apparatus 80a that will contain solids and liquids, but let gaseous
materials pass to the atmosphere. The purpose is to provide a safe method
of providing either constant or intermittent/modulated vacuum to a
physician or health provider for use on a patient or connection to a
device that may or may not be used on a patient. This device is
electronically controlled and will perform various functions including
the ability to lock-out users from changing settings to alarming
functions for safety and efficacy.

[0029]As shown in FIG. 2, system 10 may further include a disposable wound
dressing 200 for application to a wound site 250 of a patient. As
discussed further below, dressing 200 effectively seals the wound site so
that a negative pressure may be maintained at the wound site.

[0030]As shown in FIG. 2, electronically controlled suction regulator 20
may comprise any one or more of the following: a vacuum regulator 30
connected to the vacuum system 40 of the healthcare facility; a valve or
valve type system 50 (such as an electronically controlled three-way
solenoid valve or a pneumatic valve) connected to vacuum regulator 30; a
control circuit 60 powered by electrical current for controlling various
components of the regulator and for generating control signals for
controlling valve 50 so that the source of vacuum supplied to a patient
or device for predetermined periods of time is able to deliver constant
or intermittent vacuum; a flow sensor 70, such as a pressure transducer,
connected to control circuit 60 for monitoring the negative pressure
applied to a patient or device; a canister/basin 80a for collecting
fluids drained from the patient's wound; an optional second
canister/basin 80b for collecting additional fluids drained from the
patient's wound; and an optional transmitter or transceiver 90 for
transmitting information to a healthcare facility database 100 via an
optional receiver or transmitter 110.

[0031]The source of vacuum may have a vacuum between 0 and 600 mmHg, and
may be a vacuum system 40 built into a healthcare facility, such as a
distributed hospital vacuum system.

[0032]The vacuum from system 40 may be regulated by vacuum regulator 30
operating under control of control circuit 60 and may be selectively
applied continuously or intermittently or may be interrupted by valve 50.
The application of negative pressure to the wound site 250 can be
actuated at predetermined time intervals or in response to wound site
conditions such as an accumulation of fluid under the wound dressing 200.
During an intermittent vacuum mode the apparatus may vent to atmosphere
or supply low pressure oxygen to the wound during vacuum off time.

[0033]As shown in FIG. 3, control circuit 60 may comprise a programmable
digital processor 120 and a liquid crystal display or similar technology
display panel 130 connected to the other electronic circuitry. Control
circuit 60 may further include an end user interface 140 such as a touch
pad with one or more switches, connected to processor 120. Processor 120
may be programmable to turn the electronics on and off at prescribed
times. In addition, end user interface may be configured to allow an end
user to select various settings that may be employed to adjust the
characteristics (i.e., timing cycle, intermittent mode, continuous mode,
pressure, etc.) of the suction produced at the output of suction
regulator 20. In addition, The electronically controlled suction
regulator may provide the ability to lock out negative pressure settings
so that the patients cannot change settings by the healthcare providers.

[0034]Suction regulator 20 may further comprise a rechargeable battery 160
and a main power switch coupled in series with the control circuit 60 so
as to selectively power the portable device. Regulator 20 may also
include a pair of terminals for connection to a 12 VDC input for charging
the battery. Control circuit 60 may include an AC to DC converter and
regulating circuitry that may be connected to these terminals such that
regulated DC power is supplied to the electronic circuitry and the
battery 160.

[0035]Canister/basin 80a may have an adjustable proximity switch connected
to processor 120 for generating an audible using a noise emitter 150
and/or a visual alarm using an LED or LCD 130 to indicate that the
contents have reached a particular level. Canister/basin 80a may be used
with a `gel pack` and or a porous filter.

[0036]Housing 22 and canister 80a may be made from polymers for light
weight and impact resistance. Further, canister/basin 80a may be
replaceable and thus disposable and may contain about 250-1500 ml.
Canister/basin 80a may be removable and may be sealed with a gasket,
o-ring, or similar sealing apparatus. Canister/basin 80a may be frosted
to obstruct portions of view but is clear in specific areas 180 to view
contents and compare to a scale such as but not limited to ml.
Canister/basin 80a may be a portion less than a 3/4 circle but more than
a 1/4 circle and may be keyed to fit the unit 20 with an integral
incorporated into basis conduit/hose with a press fit cradle.

[0037]Electronically controlled suction regulator 20 may thus comprise a
safe regulation system with integrated (basin/canister/reservoir) and
device for preventing liquids from leaving the (basin/canister/reservoir)
thus containing possible contaminates. Further, the electronically
controlled suction regulator may comprise integrated electronics that
will regulate between 0 and 600 mmHg and provide ability to
modulate/intermittent between negative pressure and atmospheric pressure.
The electronically controlled suction regulator may have a mechanical
method for determining fluid level in canister 80a and the ability to
stop the vacuum.

[0038]Although the application described herein of suction regulator 20 is
that of negative pressure wound treatment (NPWT), suction regulator 20
may be used in a variety of applications. The electronically controlled
suction regulator is well-suited for use in healthcare facilities as a
general safe method of filtering and regulating reduced pressure for
procedures such as but not limited to: Nasopharyngeal, tracheal,
surgical, gastrointestinal, pleural, wound drainage, etc. The features
that make suction regulator 20 uniquely suited for NPWT is its ability
to: (1) allow end user adjustment of the output suction characteristics
(i.e., timing cycle, intermittent mode, continuous mode, pressure, etc.),
(2) generate an alarm if fluid in a canister reaches a particular level,
and (3) generate an alarm if the flow rate from the wound is too high
(above a threshold level), which indicates a leak. None of these features
were previously known in a suction regulator of the type applied to a
hospital's central vacuum system.

[0039]The electronically controlled suction regulator 20 may be hung on a
wall using preexisting brackets or may be placed on a bed using a clamp
or pole, or be free standing with and without an optional base and an IV
pole.

[0040]A filter/fluid trap that is permeable by gas only and not permeable
by solids or liquids may be interposed between the vacuum source and the
canister/ basin to prevent solids or liquids from being introduced into
the regulator system, the conduits, or the vacuum source. The filter may
be a porous polymer that impedes solids and liquids from passing but
allows gaseous materials to pass. The filter may be a polymer or other
natural substance. The filter may be single or plural but may cover all
conduits exiting reservoir/canister. An outlet conduit for fluid may be
connected between an outlet port of the canister and the vacuum source,
and the filter may be disposed in the canister substantially at the
interface between the outlet port and the outlet conduit.

[0041]A first pressure detector may be provided that is adapted to detect
a pressure drop indicative of the filter being substantially
covered/blocked by water or solids.

[0042]The suction regulator may further comprise an optional negative
pressure detector disposed in the inlet conduit that may compare the
measured pressure with a preset level to determine if the negative
pressure/vacuum is at or above the preset pressure level. This system
will work with a single conduit/tube and can aid in prevention of
blockage without need for separate detection systems.

[0043]The suction regulator electronics may be configured to time stamp
the proximity switches position by operator. As explained further below,
such time stamps and switch positions may be supplied to the healthcare
facility's records database.

[0044]The electronics logic may be configured to protect patients by
alarming if too much fluid is contained in the canister in a pre-entered
time frame.

[0045]According to one embodiment of the present invention, the regulator
system 10 is used for applying a negative pressure to a wound. This may
be accomplished by connecting the outlet conduit of the suction regulator
20 to the patient interface portion 200 (i.e., the portion to which a
portable pump was previously attached) of the systems disclosed in U.S.
Pat. Nos. 4,382,441, 4,392,858, 4,655,754, 4,826,494, 4,969,880,
5,100,396, 5,261,893, 5,527,293, 5,636,643, 5,645,081, 6,071,267,
6,117,111, 6,135,116, 6,142,982, 6,174,306, 6,345,623, 6,398,767,
6,520,982, 6,553,998, 6,814,079, 7,198,046, and 7,216,651, the entire
disclosures of which are incorporated herein by reference. By replacing
the pump of those systems with a regulated connection to the distributed
vacuum system in a healthcare facility, the added expense and maintenance
of such pumps may be avoided.

[0046]FIGS. 4-12B relate to disposable wound dressings 200 that may be
used in the inventive system. The disposable wound dressings shown in
FIGS. 4-12B are described below and are described in commonly-assigned
U.S. Provisional Patent Application No. 61/041,301, entitled "WOUND
TREATEMENT SYSTEM," filed on Apr. 1, 2008, by Pat E. Eddy et al., the
entire disclosure of which is incorporated herein by reference. FIGS. 4-7
show an example of one wound treatment system to which the various
improvements may be implemented separately or in various combinations.
FIG. 4 is a perspective view of a disposable wound dressing 200.
Disposable wound dressing 200 includes wound drape 222 that includes an
interior portion 224 surrounded by a perimeter 226. Drape 222 further
includes a skin contact surface 228 with an adhesive coating 230. The
drape may be made of membrane permeable, semi-permeable or non-permeable
materials that are commercially available, an example being material
referred to as TAGODERM®, which is available from the 3M (Minnesota
Mining and Manufacturing) Company of St. Paul, Minn. A protective backing
223 is placed over the adhesive coating 230 on the skin contact surface
228 until drape 222 is ready for application.

[0047]Wound drape 222 may comprise a pair of panels 219 with inner,
upturned edges 220 which can be adhesively joined together to form a seam
221 which extends transversely across drape 222 and projects generally
upwardly therefrom. The panels 219 can be secured together at the seam
221 by the adhesive coating 230 to form the seam 221. Alternatively,
drape 222 may be made of a single panel as described further below.

[0048]The vacuum conduit may include a tube or sheath 234 includes a
proximate end 36 located under drape 222 and a distal or free end 238.
The tube 234 can be inserted through the seam 21 which forms an opening
232 between the panel edge strips 220 at approximately the center of the
drape 222. If a single panel 219 is used such that no seam is present, a
hole may be formed in the drape 222 for passage of the tube or for
placement of an attachment pad or coupler (discussed below). A relatively
short length of the tube 234 adjacent to its proximate end 236 is shown
under the drape 222 in FIG. 5, but greater lengths of the tube 234 could
be placed under the drape 222. As shown in FIG. 7, the tube proximate end
36 is open, and adjacent to the proximate end 236 one or more openings
are formed. The tube opening(s) 239 may project downwardly, i.e. away
from the skin contact surface 228. The short length of the tube 234,
which is located under drape 222, can be releaseably secured to the skin
contact surface 228 by the adhesive coating 230, preferably with the tube
opening 239 facing downwardly. The tube 234 may have a length that is
sufficient to extend to the vacuum source 242 or to the containment
apparatus 241. Alternatively, a second tube may be attached to the free
end 238 of the tube 234.

[0049]The tube 234 can comprise, for example, a flexible, plastic tube of
the type that is commonly used as a percutaneous sheath for intravenous
treatments. At its distal end 238, the tube 234 may be adapted for: (1)
closure with a variety of suitable closure devices; (2) connection to
various active and passive fluid collection devices for draining and
evacuating fluid from the wound site; and (3) connection to various fluid
source devices for actively and passively introducing fluid to the wound
site.

[0050]FIG. 5 shows the tube distal end 238 fluidically communicating with
a suction regulator 20 for actively draining fluid from the wound site.

[0051]The disposable wound dressing 200 may further include a wound
dressing pad 225 between the wound site 250 and drape 222. The wound
dressing pad 225 can comprise a variety of materials with varying
properties such as: (1) absorbency; (2) wicking or capillary action; and
(3) surface contact action. The wound dressing 225 is primarily located
in a chamber 246 formed between the wound 250 and the drape 222.

[0052]In wound treatment systems such as the one described above, the
wound dressing pad 225 is sized and shaped to fit in and over the wound
to be treated, and thus the wound dressing is in direct contact with the
wound. In prior systems, a gauze or foam is used as the wound dressing
pad so as to allow air to flow around the wound. The air flow is caused
by the application of a vacuum. Because the vacuum also tends to draw
fluids from the wound and through the wound dressing pad, the wound
tissue can grow into the wound dressing pad or otherwise stick to the
wound dressing pad. This causes problems in that the wound does not heal
properly and can also reopen when the wound dressing is removed or
changed. In addition, the removal of a wound dressing pad that is stuck
to the wound, can be particularly uncomfortable for the patient.

[0053]Wound dressing pad 25 may be siliconized to allow tissue on and
around the wound to form without growing into or onto the wound dressing
pad or from otherwise sticking to the wound tissue. The wound dressing
pad may include a natural fiber, polymer, foam (such as a
granufoam-urethane base or whitefoam-PVA base), or other filler/support
material. An example of a foam is a granufoam available from Kinetic
Concepts, Inc. (KCI) of San Antonio, Tex. The filler/support material
could be "siliconized." This can occur by applying silicone to at least
the surface of the filler/support material that directly contacts the
wound, by impregnating the filler/support material with silicone, or by
using a filler/support material that already integrally includes silicone
or its equivalent. By using silicone or an equivalent, the wound can
properly heal without the wound tissue growing into or sticking to the
wound dressing pad. One commercially available material that may be used
as the wound dressing is THERAGAUZE®, which is available from Soluble
Solutions, LLC of Newport News, Va. The formulation of THERAGAUZE® is
believed to be disclosed in U.S. Pat. No. 6,592,860, the entire
disclosure of which is incorporated herein by reference. Alternatively,
one may use foam that is seared to close cells on the foam surface
adjacent the wound, or use a dual-density foam (two styles of foam
together for different end effects) as shown in FIGS. 12A and 12B.
Specifically, the dual density foam pad 225 includes a larger cell foam
layer 225a and a smaller cell foam layer 225b that contacts the wound. As
shown in FIG. 12B, the foam pad 225 may further include an optional
coating 225c of a material such as silicone.

[0054]The silicone/seared foam may or may not be perforated or slit to
allow vacuum, ambient or a positive pressure to pass through, and to
allow liquids to pass. Whether to perforate or slit the silicone will
depend upon the particular application and the nature of the
filler/support material and how the silicone is provided.

[0055]The siliconized wound, seared, duel density dressing pads 225 may be
coated with a medicated or non-medicated solution such as polypropylene,
glycol and saline, silver, an anti-bacterial solution or the like, that
may promote healing and/or reduce adhesion of tissue and fluids.

[0056]Alternatively, wound dressing pad 225 is made of a bio-absorbable
material such that wound tissue growth into pad 225 because a positive
condition rather than a negative condition as the pad may simply be left
in place into the patients body absorbs the pad.

[0057]The wound drape 222 may be any conventional drape material known to
be used for vacuum-assisted wound treatment. The material may be a
semi-permeable or impermeable flexible covering that may or may not have
a valve/relief to the outside atmosphere. The wound drape may have one or
more apertures for allowing a tube, attachment pad, or other coupler to
be inserted for connection of the vacuum conduit and application of the
vacuum to the wound. The application of the vacuum may be regulated and
varied during a course of treatment. In addition, the vacuum may be
intermittently applied.

[0058]The system may use a tube that has a plurality of apertures through
its sidewalls at the end of the tube that extends into and under the
wound drape. The end of the tube may lie between the drape and the wound
dressing or it may extend into the wound dressing.

[0059]An attachment pad/coupler has been developed that includes a
mechanical device to provide a visual acknowledgement of vacuum at a
predetermined level at or near the wound site. In general, an attachment
pad/coupler 300 such as that shown in FIGS. 8-11, comprises a flange
portion 330 having a tapered edge 331, and a profile which may be of any
desired shape. On the face of the flange 330 that intended for contact
with the wound dressing pad 225 are one or more projections 332. The
purpose of these projections is to provide one or more fluid channels 333
facilitating the flow of fluids form any point of the flange to a central
aperture 334, from which it is intended to apply suction. The attachment
pad 300 includes a connector 335, located above the aperture 334, having
a tubular end 336 adapted for receiving and connecting to the vacuum
conduit. The tubular and may have an outwardly tapered portion to
facilitate feeding a tube into the connector. The upper surface 337 of
the attachment pad 300 has a substantially smooth surface with the
exception of a bubble or dome 340 (described further below). Linear
attachment may be used in lieu of the attachment pad/coupler.

[0060]In use, the connector portion 335 is sized so that it extends
through the aperture 325 in the wound drape 222 shown in FIGS. 9 and 10,
with the adhesive surface around the aperture bonded to the smooth
surface 337 of the flange 330. The flange 330 of the attachment pad 300
may be circular as shown in FIG. 11. Alternatively, the flange may be any
other shape.

[0061]FIGS. 10 and 11 show the attachment pad 300 attached to a wound site
250 of a patient 370. The attachment pad 300 is pressed into firm contact
with wound dressing pad 225, which is itself pressed into contact with a
wound area 250. The attachment pad 300 and wound dressing pad 225 are
pressed into contact with the wound area by a wound drape 222. The
adhesive surface 330 of drape 222 is bonded to the patient's skin outside
the periphery of the wound dressing pad 225 and attachment pad 300. It is
also bonded to upper surface 337 of the attachment pad 300. Aperture 325
is formed in the drape 222 to permit the connector portion 335 to extend
upwardly through the drape.

[0062]As mentioned above, attachment pad 300 has a convex bubble or dome
340 formed in one of its surfaces, that is sucked inward increasing
vacuum pressure at our near the wound site 250. The size, thickness, and
material used for the bubble or dome could be used to calculate an
approximate vacuum recognition that would be changeable in the mold
itself. The attachment pad 300 could include multiple bubbles that each
indicating different vacuum levels such as 50, 100, and 150 mm Hg.

[0063]An attachment pad such as those disclosed in U.S. Pat. Nos.
6,345,623, 6,553,998, and 6,814,079 may also be used with the inventive
system. In addition, a TRACKPAD® available from KCI may also be
employed.

[0064]As noted above, the wound treatment system 10 may include two
canisters 80a and 80b (FIG. 2). Existing systems use a single canister
that has an alarm that is triggered when the canister becomes full. When
the canister becomes full, the vacuum system is stopped until the
healthcare professional overseeing the treatment of the patient, can get
to the room, remove and empty the canister, return the canister, and
restart the system. All of this takes time and interrupts the procedure.
By using two canisters, a first canister can be used in the normal
course, and when the alarm is generated, a signal is sent to an
electronically controlled valve that diverts the flow of fluid from the
first canister 80a to the second canister 80b to thereby allow
uninterrupted use. When the alarm is generated indicating the first
canister 80a is full, the healthcare professional overseeing the
treatment of the patient, can empty the first canister as was done
previously, except that the system can keep operating with the fluid
flowing to the second canister 80b. Upon returning the empty first
canister 80a, the system can either automatically return the flow of
fluid to the first canister 80a or continue the flow of fluid to the
second canister 80b until such time that it becomes full--at which time
the valve may be reactuated to divert the flow to first canister 80a.

[0065]The level of fluid in the canisters 80a, 80b may be monitored using
a continuity sensor that includes two electrically conductive terminals
spaced apart at the upper internal region of the canisters such that
current flows from one terminal to the other only when the fluid level
reaches the terminals thereby causing an alarm.

[0066]Flow sensor 70 may be used to monitor the pressure of the vacuum and
determines if a predetermined start up pressure lasts for a certain time.
This feature (also known as "wound close technology") allows one to
monitor the progression of the wound to closure. This can be displayed on
display screen 130 and would work as an initial start cycle function that
can be done at a new wound site, change of dressing, or as a special
cycle that will work when the wound site is at ambient/atmospheric
pressure.

[0067]A valve mechanism at the attachment pad or elsewhere that allows
ambient air to be vented to the wound at 1 or 2 psi whenever the vacuum
is in an off interval of an intermittent cycle or the vacuum is removed.

[0068]The system may also be configured to a high flow (leak detection)
alarm that is activated when the flow of air from the wound site is above
a threshold.

[0069]Referring back to FIG. 2, optional transmitter/transceiver 90 may be
provided to transmit information to a receiver/transceiver 110 that
receives the information and provides it to an automated records database
100 of the healthcare facility. The information may include any one or
more of the following: the times at which negative pressure was applied
to the wound, the pressure applied, the intermittence cycles, the times
at which the settings were changed along with the new settings, leak
detection alarm times, full canister alarms times, and readings from flow
sensor 70 which allows one to monitor the progression of the wound to
closure. Transmitter/transceiver 90 may be coupled wirelessly or by wired
connection such as USB. The database 100 may be a database such as a
Cerner records database.

[0070]Each of the above-noted features may be implemented separately from
the other features, or in combination with one or more of the other
features.

[0071]The above description is considered that of the preferred
embodiments only. Modification of the invention will occur to those
skilled in the art and to those who make or use the invention. Therefore,
it is understood that the embodiments shown in the drawings and described
above are merely for illustrative purposes and not intended to limit the
scope of the invention, which is defined by the following claims as
interpreted according to the principles of patent law, including the
Doctrine of Equivalents.